<!DOCTYPE html>
<html>
  <head>
    <style>
      input ~ label {color: red}
      input[checked]:checked ~ label {color: green}
      input[checked]:checked:not(:default) + label {color: red}
    </style>
  </head>
  <body onload='var e1 = document.getElementById("one");
                var l1 = document.getElementById("l1");
                e1.parentNode.removeChild(e1);
                l1.parentNode.removeChild(l1);
                document.getElementById("two").setAttribute("checked", "true");'>
    <form>
      <input type="checkbox" name="group1" id="one" value="1" default="true" checked/>
      <label id="l1" for="one">Should be no red</label><br>
      <input type="checkbox" name="group1" id="two" value="2"/>
      <label for="two">Should be no red</label>
      <input type="checkbox" name="group1" id="three" value="3"/>
      <label for="three">Should be no red</label>
    </form>
  </body>
</html>
